Laravel 4.2: Can't Use Transformer with DB::Raw Query - laravel

Question

Throughout my app, I have been taking the results of an Eloquent query and channeling it through a transformer and it is working well. This is what I am doing:
public function index()
{
$users = User::with('profile', 'location', 'role')->get();
return $this->respond([
'data' => $this->userTransformer->transformCollection($users->all())
]);
}
However, I ran into a situation where to produce a nested resource I needed to use a DB::RAW query
public function byLoan($id)
{
$users = DB::select( DB::raw("SELECT * FROM users WHERE id IN (SELECT DISTINCT(user_id) FROM farms WHERE user_id = {$id})") );
return $this->respond([
'data' => $this->userTransformer->transformCollection($users->all())
]);
}
The code above gave me this error "Symfony \ Component \ Debug \ Exception \ FatalErrorException (E_ERROR) Call to a member function all() on array".
I changed transformCollection($users->all()) to transformCollection($users) and now the error is this "Symfony \ Component \ Debug \ Exception \ FatalErrorException (E_ERROR) Cannot use object of type stdClass as array".
I don't know what else to try.
My Transformer class looks like this:
<?php namespace Acme\Transformers;
abstract class Transformer {
public function transformCollection(array $items)
{
return array_map([$this, 'transform'], $items);
}
public abstract function transform($item);
}
And the UserTransformer implentation:
<?php namespace Acme\Transformers;
class UserTransformer extends Transformer
{
public function transform($arr)
{
//return $arr;
return [
'id' => $arr['id'],
'username' => $arr['username'],
'abr' => $arr['abr'],
'email' => $arr['email'],
'phone' => $arr['phone'],
'role_id' => $arr['role_id'],
'role_abr' => $arr['role']['abr'],
'role' => $arr['role']['role'],
'loc_id' => $arr['location']['id'],
'loc_abr' => $arr['location']['loc_abr'],
'region_id' => $arr['location']['region_id'],
'is_admin' => (boolean) $arr['is_admin'],
'is_manager' => (boolean) $arr['is_manager'],
'show_agency' => (boolean)$arr['profile']['show_agency'],
'show_balance_due' => (boolean)$arr['profile']['show_balance_due'],
'show_close_date' => (boolean)$arr['profile']['show_close_date'],
'show_commit_arm' => (boolean)$arr['profile']['show_commit_arm'],
'show_region' => (boolean)$arr['profile']['show_region'],
'show_season' => (boolean)$arr['profile']['show_season']
];
}
}

Answer 1

First off, don't use all() on a DB::select. The select method does execute the query as soon as it's called. Also all() is for Eloquent models only.
However the bigger problem here, is how a Query Builder result is structured. Its an array (of all rows) filled with objects (the individual row, with properties for each column)
So that means, passing it to your transform method and then accessing the columns like an associative array doesn't work. Example:
$arr['id']
What you would have to do instead is:
$arr->id // obviously the name $arr doesn't make any sense now because its an object..
If this messes up the other usages of transform() you should also be fine by just adding
$arr = (array) $arr;
at the beginning of the function. This converts the object into an array and makes sure you can access it like $arr['id']